In countries where traditional medicine is practiced, particularly in the East, it has been estimated that up to 80% of the population continues to use these traditional methods to treat primary medical problems. In the past decade or so, research has been increasingly focused on scientific evaluation of traditional medicines and drugs of plant and herbal origin, including methods derived from indigenous or tribal populations.
One such herb is Ashwagandha (Withania somnifera), so named in Sanskrit denoting its rejuvenative or vital properties (ashwa: horse; gandha: smell), which is said to confer the strength and vitality of a horse. This herb has long been used in the Ayurvedic formulary of India. Ashwagandha is commonly referred to as “Indian Ginseng” because of its beneficial properties. See, M. S. Premila, Ayurvedic Herbs: A Clinical Guide to the Healing Plants of Traditional Indian Medicine (2007, The Haworth Press, New York).
Herbalists have identified Ashwagandha as an adaptogen. The term “adaptogen” is used herein to refer to natural herb products which are believed to increase the body's resistance to stress, trauma, anxiety and fatigue. In the past, adaptogens have been called rejuvenating herbs, restoratives, qi (i.e. “chi”) tonics, or rasayanas. While not intending to be bound by theory, it has been proposed that adaptogenic herbs have a “normalizing effect” on the body and may be capable of either toning down the activity of hyperfunctioning body systems, or strengthening the activity of hypofunctioning body systems. For example, it has been proposed that adaptogenic herbs have the ability to balance endocrine system hormones and the immune system, and thus help the body to maintain homeostasis.
Other well known herbal adaptogens include licorice, ginseng, Reishi, and Astragalus. These useful herbs have been often studied in recent years as components in nutraceuticals, dietary supplements, and as dietary ingredients in functional foods.
Another compound associated with relaxation and reduction of stress is L-theanine (N-ethyl-L-glutamine), which is a component found in both green and black tea. Tea is the only significant dietary source of L-theanine, and it has been proposed that L-theanine can induce a relaxed state. As an amino acid derivative, L-theanine rapidly crosses the blood-brain-barrier and thereby acts directly on the brain. L-theanine has been studied in combination with caffeine, which reveals synergistic effects in cognition and mood (C. F. Haskell, et al., Biol. Psychol. (2008) 77: 113-122).
The adaptogenic properties of Ashwagandha herb would appear to complement the anti-stress property of L-theanine. If Ashwagandha herb and L-theanine were combined, the resulting nutraceutical would provide a useful contribution to the art.
In view of the above, there is a need and a desire for a dietary supplement and/or functional food including Ashwagandha herb and L-theanine in combination, that exploits the potential beneficial properties of both components in a readily bioavailable formulation.